The present disclosure is directed to a system for mechanical die-based manufacture of threaded fasteners.
Thread rolling to manufacture bolts, screws, and other threaded fasteners requires rapid rolling of fastener blanks between a mobile die and a stationary die to form the thread. The manufacturing apparatus reciprocates the mobile die back and forth relative to the stationary die at a high rate of speed, often hundreds of reciprocations in a minute. Because many different blank and thread configurations may be used with and required from one manufacturing apparatus, numerous different dies can be interchangeably used with the same machine. While switching out dies may change the thread patterns, accommodating the different size and shape of the blanks usually falls to the die holders of the apparatus. Such holders typically include an adjustment mechanism which can alter the location and angulation of the dies to accommodate different blanks.
All current manufacturing equipment requires adjustment to the pressure and distance between the faces of the dies, and occasionally the angulation of one or both of the dies. The industry's standard practice uses a threaded adjustment to properly position the die faces. Operators may require several years of training to learn the appropriate “feel” required for current adjustment methods to produce good fasteners, often resulting in unusable batches of product during the long training period. Furthermore, such adjustment mechanisms can be shifted out of position accidentally or over the course of production. Moreover, due to the rapid reciprocating movement of the mobile die and its respective mobile die holder, as well as the cantilevered positioning of the mobile die holder on the apparatus, the mobile die holder may be subject to forces which move it out of alignment, creating further waste of time and material.
It is therefore the object of this application to provide a die positioning system which provides accurate, easily reproducible positioning of at least one die and its corresponding die holder over long periods of high use.